arch/um/drivers/mconsole_user.c

   1 /*
   2  * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org)
   3  * Copyright (C) 2001 - 2003 Jeff Dike (jdike@addtoit.com)
   4  * Licensed under the GPL
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <errno.h>
  10 #include <signal.h>
  11 #include <sys/socket.h>
  12 #include <sys/types.h>
  13 #include <sys/uio.h>
  14 #include <sys/un.h>
  15 #include <unistd.h>
  16 #include "user.h"
  17 #include "mconsole.h"
  18 #include "umid.h"
  19
  20 static struct mconsole_command commands[] = {
  21         /* With uts namespaces, uts information becomes process-specific, so
  22          * we need a process context.  If we try handling this in interrupt
  23          * context, we may hit an exiting process without a valid uts
  24          * namespace.
  25          */
  26         { "version", mconsole_version, MCONSOLE_PROC },
  27         { "halt", mconsole_halt, MCONSOLE_PROC },
  28         { "reboot", mconsole_reboot, MCONSOLE_PROC },
  29         { "config", mconsole_config, MCONSOLE_PROC },
  30         { "remove", mconsole_remove, MCONSOLE_PROC },
  31         { "sysrq", mconsole_sysrq, MCONSOLE_INTR },
  32         { "help", mconsole_help, MCONSOLE_INTR },
  33         { "cad", mconsole_cad, MCONSOLE_INTR },
  34         { "stop", mconsole_stop, MCONSOLE_PROC },
  35         { "go", mconsole_go, MCONSOLE_INTR },
  36         { "log", mconsole_log, MCONSOLE_INTR },
  37         { "proc", mconsole_proc, MCONSOLE_PROC },
  38         { "stack", mconsole_stack, MCONSOLE_INTR },
  39 };
  40
  41 /* Initialized in mconsole_init, which is an initcall */
  42 char mconsole_socket_name[256];
  43
  44 int mconsole_reply_v0(struct mc_request *req, char *reply)
  45 {
  46         struct iovec iov;
  47         struct msghdr msg;
  48
  49         iov.iov_base = reply;
  50         iov.iov_len = strlen(reply);
  51
  52         msg.msg_name = &(req->origin);
  53         msg.msg_namelen = req->originlen;
  54         msg.msg_iov = &iov;
  55         msg.msg_iovlen = 1;
  56         msg.msg_control = NULL;
  57         msg.msg_controllen = 0;
  58         msg.msg_flags = 0;
  59
  60         return sendmsg(req->originating_fd, &msg, 0);
  61 }
  62
  63 static struct mconsole_command *mconsole_parse(struct mc_request *req)
  64 {
  65         struct mconsole_command *cmd;
  66         int i;
  67
  68         for(i=0;i<sizeof(commands)/sizeof(commands[0]);i++){
  69                 cmd = &commands[i];
  70                 if(!strncmp(req->request.data, cmd->command,
  71                             strlen(cmd->command))){
  72                         return(cmd);
  73                 }
  74         }
  75         return(NULL);
  76 }
  77
  78 #define MIN(a,b) ((a)<(b) ? (a):(b))
  79
  80 #define STRINGX(x) #x
  81 #define STRING(x) STRINGX(x)
  82
  83 int mconsole_get_request(int fd, struct mc_request *req)
  84 {
  85         int len;
  86
  87         req->originlen = sizeof(req->origin);
  88         req->len = recvfrom(fd, &req->request, sizeof(req->request), 0,
  89                             (struct sockaddr *) req->origin, &req->originlen);
  90         if (req->len < 0)
  91                 return 0;
  92
  93         req->originating_fd = fd;
  94
  95         if(req->request.magic != MCONSOLE_MAGIC){
  96                 /* Unversioned request */
  97                 len = MIN(sizeof(req->request.data) - 1,
  98                           strlen((char *) &req->request));
  99                 memmove(req->request.data, &req->request, len);
 100                 req->request.data[len] = '\0';
 101
 102                 req->request.magic = MCONSOLE_MAGIC;
 103                 req->request.version = 0;
 104                 req->request.len = len;
 105
 106                 mconsole_reply_v0(req, "ERR Version 0 mconsole clients are "
 107                                   "not supported by this driver");
 108                 return(0);
 109         }
 110
 111         if(req->request.len >= MCONSOLE_MAX_DATA){
 112                 mconsole_reply(req, "Request too large", 1, 0);
 113                 return(0);
 114         }
 115         if(req->request.version != MCONSOLE_VERSION){
 116                 mconsole_reply(req, "This driver only supports version "
 117                                STRING(MCONSOLE_VERSION) " clients", 1, 0);
 118         }
 119
 120         req->request.data[req->request.len] = '\0';
 121         req->cmd = mconsole_parse(req);
 122         if(req->cmd == NULL){
 123                 mconsole_reply(req, "Unknown command", 1, 0);
 124                 return(0);
 125         }
 126
 127         return(1);
 128 }
 129
 130 int mconsole_reply_len(struct mc_request *req, const char *str, int total,
 131                        int err, int more)
 132 {
 133         struct mconsole_reply reply;
 134         int len, n;
 135
 136         do {
 137                 reply.err = err;
 138
 139                 /* err can only be true on the first packet */
 140                 err = 0;
 141
 142                 len = MIN(total, MCONSOLE_MAX_DATA - 1);
 143
 144                 if(len == total) reply.more = more;
 145                 else reply.more = 1;
 146
 147                 memcpy(reply.data, str, len);
 148                 reply.data[len] = '\0';
 149                 total -= len;
 150                 str += len;
 151                 reply.len = len + 1;
 152
 153                 len = sizeof(reply) + reply.len - sizeof(reply.data);
 154
 155                 n = sendto(req->originating_fd, &reply, len, 0,
 156                            (struct sockaddr *) req->origin, req->originlen);
 157
 158                 if(n < 0) return(-errno);
 159         } while(total > 0);
 160         return(0);
 161 }
 162
 163 int mconsole_reply(struct mc_request *req, const char *str, int err, int more)
 164 {
 165         return mconsole_reply_len(req, str, strlen(str), err, more);
 166 }
 167
 168
 169 int mconsole_unlink_socket(void)
 170 {
 171         unlink(mconsole_socket_name);
 172         return 0;
 173 }
 174
 175 static int notify_sock = -1;
 176
 177 int mconsole_notify(char *sock_name, int type, const void *data, int len)
 178 {
 179         struct sockaddr_un target;
 180         struct mconsole_notify packet;
 181         int n, err = 0;
 182
 183         lock_notify();
 184         if(notify_sock < 0){
 185                 notify_sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 186                 if(notify_sock < 0){
 187                         err = -errno;
 188                         printk("mconsole_notify - socket failed, errno = %d\n",
 189                                err);
 190                 }
 191         }
 192         unlock_notify();
 193
 194         if(err)
 195                 return(err);
 196
 197         target.sun_family = AF_UNIX;
 198         strcpy(target.sun_path, sock_name);
 199
 200         packet.magic = MCONSOLE_MAGIC;
 201         packet.version = MCONSOLE_VERSION;
 202         packet.type = type;
 203         len = (len > sizeof(packet.data)) ? sizeof(packet.data) : len;
 204         packet.len = len;
 205         memcpy(packet.data, data, len);
 206
 207         err = 0;
 208         len = sizeof(packet) + packet.len - sizeof(packet.data);
 209         n = sendto(notify_sock, &packet, len, 0, (struct sockaddr *) &target,
 210                    sizeof(target));
 211         if(n < 0){
 212                 err = -errno;
 213                 printk("mconsole_notify - sendto failed, errno = %d\n", errno);
 214         }
 215         return(err);
 216 }
 217
 218 /*
 219  * Overrides for Emacs so that we follow Linus's tabbing style.
 220  * Emacs will notice this stuff at the end of the file and automatically
 221  * adjust the settings for this buffer only.  This must remain at the end
 222  * of the file.
 223  * ---------------------------------------------------------------------------
 224  * Local variables:
 225  * c-file-style: "linux"
 226  * End:
 227  */